The information on this page is for informational purposes only and does not constitute medical advice. Consult your genetic counselor or specialist physician for treatment decisions.
What is hereditary hearing loss?
Hereditary hearing loss is sensorineural hearing loss caused by genetic mutations, present at birth or appearing in early childhood. Roughly 50–60% of all congenital deafness is genetic in origin.
The most frequently mutated genes
The most common single-gene cause of hereditary deafness, accounting for around 60% of autosomal recessive non-syndromic hearing loss. It affects an estimated 18 million people worldwide.
- Most frequent variants: c.35delG (Europe), c.235delC (East Asia)
- Gene therapy status: Preclinical
- Lead programme: Sensorion SENS-601 — CTA filing targeted for 2026
- Full hearing restoration in a primate model was published in 2025 (Nature Communications)
A protein involved in synaptic vesicle fusion in inner ear hair cells. Mutations cause auditory neuropathy spectrum disorder, affecting an estimated 2 million people.
- Gene therapy status: Phase 1/2 — active clinical trials
- Hearing restoration was demonstrated in six children in China using a dual AAV vector approach (2024)
- Regeneron/Decibel Therapeutics and Akouos/Eli Lilly are running active programmes
Gene therapy approaches
- AAV vector: delivers a healthy copy of the gene into inner ear cells
- Dual vector: splits delivery across two AAVs for large genes such as OTOF
- CRISPR: direct correction of the mutation in genes such as GJB2 (preclinical)
Open challenges
- GJB2: Connexin 26 is expressed in both epithelial and fibrocyte cells, making targeting complex
- OTOF: the gene exceeds AAV packaging capacity, requiring a dual-vector approach
- Safe surgical access to the inner ear (techniques still being developed)
- Treatment window: early intervention is critical for auditory cortex development
This is not medical advice. Consult your specialist.